From Mat Honan at Wired:
Apple tech support confirmed to me twice over the weekend that all you need to access someone’s AppleID is the associated e-mail address, a credit card number, the billing address, and the last four digits of a credit card on file. I was very clear about this. During my second tech support call to AppleCare, the representative confirmed this to me. “That’s really all you have to have to verify something with us,” he said.
Here’s a solid reminder to check out your own security verification methods. Is your support team using something similar to Apple and Amazon?